1. Field of the Invention
The present invention relates to a virtual object display apparatus and method to display motions of objects, including humans at high speed usings computer-graphics system.
2. Description of the Related Art
Conventionally, in the case of displaying action of an object, having plural elements connected by a link structure, using computer-graphics, calculation of inverse-kinematics or physical rules is executed for each object. If the motion of the object is displayed at real time while the motion of the object is simulated, the calculation-load causes a decrease of an update-rate of drawing the motion of the object on the display screen in proportion to a number of the objects.
In such a case, a human model or a model of some other living things is represented as an object composed of a plurality of elements (a head, a body, a right arm, a left arm, a right hand, a left hand, a right leg, a left leg, a right foot, a left foot). The plurality of elements are connected by a link structure. Therefore, in the case of displaying the action of the object by computer-graphics, a few objects or simple actions of the object are only displayed because of the above-mentioned calculation-load.
In the case of displaying a lot of objects, it is impossible to draw coordinate points of the objects on the display screen in real time. In this case, drawing of the objects is executed by unit of frame in non-real time. After creating all frames, the user watches the frames by playing as a video image. However, in this method, it is impossible for the user to interactively designate an motion of the object on the display screen. For example, in the case of simulation-display of the flow of a lot of humans in the street, it is only possible for the user to watch the action of many humans without interactive designation.
In short, in the case of displaying the action of a lot of objects using computer-graphics, it takes a long time to draw the motion of a lot of objects on the display screen because of the calculation-load of the motion of each object. Therefore, it is impossible for the user to watch the motion of the objects in real-time.